Armoni M, Rafaeloff R, Barzilai A, Eitan A, Karnieli E
Department of Internal Medicine C, Technion-Israel Institute of Technology, Haifa.
J Clin Endocrinol Metab. 1987 Dec;65(6):1141-6. doi: 10.1210/jcem-65-6-1141.
We examined the effects of insulin on glucose transport and subcellular glucose transporter distribution in isolated omental adipose cells from men and women. 3-O-Methylglucose transport was measured in intact cells, and the number of glucose transporters in plasma membranes and low density microsomal membranes was determined using the cytochalasin B binding assay. Compared to adipocytes from women, omental adipocytes from men were characterized by 1) 2-fold larger cell volume; 2) 4- to 5- and 2.5-fold higher glucose transport rates when calculated per cell or per cell surface area, respectively, in either basal or insulin-stimulated cells; 3) similar 2-fold insulin stimulating effect per se; and 4) equal concentrations of transporters in both fractions examined, but a 2-fold increase in their total number per cell. Additionally, although not directly measured, the calculated glucose transporter activity in basal plasma membranes prepared from adipocytes from men was 2.7-fold higher than that in women, and insulin further induced a 30% increase in that activity. Thus, a sex-related difference was found between the number of glucose transporters per cell and the resultant glucose transport activity of the intact cells. Together with the increased specific activity of glucose transporters in men compared to women, our findings indicate a sex-related difference in adipocyte glucose transport, mainly due to an increase in the number and modulation of the intrinsic activity of glucose transporters in the plasma membrane.
我们研究了胰岛素对来自男性和女性的分离网膜脂肪细胞中葡萄糖转运及亚细胞葡萄糖转运体分布的影响。在完整细胞中测量3 - O - 甲基葡萄糖转运，并使用细胞松弛素B结合试验测定质膜和低密度微粒体膜中葡萄糖转运体的数量。与来自女性的脂肪细胞相比，来自男性的网膜脂肪细胞具有以下特征：1）细胞体积大2倍；2）在基础或胰岛素刺激的细胞中，按每个细胞或每个细胞表面积计算，葡萄糖转运速率分别高4至5倍和2.5倍；3）胰岛素本身具有相似的2倍刺激作用；4）在所检测的两个组分中转运体浓度相等，但每个细胞中转运体总数增加2倍。此外，虽然未直接测量，但从男性脂肪细胞制备的基础质膜中计算出的葡萄糖转运体活性比女性高2.7倍，胰岛素进一步使该活性增加30%。因此，发现每个细胞中葡萄糖转运体的数量与完整细胞的葡萄糖转运活性之间存在性别相关差异。与女性相比，男性葡萄糖转运体的比活性增加，我们的研究结果表明脂肪细胞葡萄糖转运存在性别相关差异，主要是由于质膜中葡萄糖转运体数量增加及其内在活性的调节。
